In recent years, enterprises have shifted much of their computing needs from enterprise owned and operated computer systems to cloud computing providers. Cloud computing providers charge enterprises to store and run their applications in a cloud-computing facility and allow enterprises to purchase other computing services in much the same way utility customers purchase a service from a public utility. A typical cloud-computing facility is composed of numerous racks of servers, switches, routers, and mass data-storage devices interconnected by local-area networks, wide-area networks, and wireless communications that may be consolidated into a single data center or distributed geographically over a number of data centers. Enterprises typically run their applications in a cloud-computing facility as virtual machines (“VMs”) that are consolidated into a virtual data center (“VDC”) also called a software defined data center (“SDDC”). A VDC recreates the architecture and functionality of a physical data center for running an enterprise's applications. Because the vast numbers of VDCs and dynamic nature of VDCs running in a typical cloud-computing facility, VDC's introduce management challenges to information technology (“IT”) managers. Many IT managers lack the insight needed to objectively identify and prioritize VDC strengths and weaknesses. While numerous internal metrics exists to evaluate the performance of hardware and VM's running in a typical data center, IT managers often find it difficult to evaluate and rank VDC performance based these internal metrics.